Fuel pump and control system



Nov. 3, 1953 r. R. THOREN FUEL PUMP AND CONTROL SYSTEM 2 Sheets-Sheet l Filed June 25, 1948 Nov. 3, 1953 T. R. THoRl-:N 2,657,635

FUEL PUMP AND`CONTROL SYSTEM Filed June 25, 1948 2 Sheets-Sheet 2 liz? Patented Nov. 3, 1953 FUEL PUMP AND CONTROL SYSTEM Theodore E. Thoren, Chagrin Falls, Ohio, as-

slgnor to Thompson Products, Inc., Cleveland, Ohio, a corporation of Ohio Application June 25, 1948, Serial No. 35,253

This invention relates to an improved pump particularly adapted for use in the fuel. system of an internal combustion engine and to an improved control system for such pump for controlling the operation of the pump in response to certain operating characteristics of an internal combustion engine.

Fuel pumps heretofore employed in the fuel systems of automotive internal combustion engines have generally been mechanically driven by the engine, such as through a suitable connection to the cam or crank shaft of the engine. Such a drive arrangement necessarily required that the pump be mounted as close as possible to the engine, and it necessarily followed that the pump was located a substantial distance from the fuel tank of the particular automotive vehicle and- 6 Claims. (Cl. 10S-42) this reason the type of fuel pump heretofore genf.

erally employed in automotive vehicles has been the so-called diaphragm type of pump wherein a diaphragm member Was reciprocated by a mechanical connectionto the cam shaft of the engine. Even the best designs of diaphragm type pumps require a unit of substantial size, and furthermore, such pumps do not have the best suction properties.

It has heretofore been proposed, and the proposal has been Widely used in aircraft fuel systems, that the fuel pump be submerged in the fuel tank. While such an arrangement has advantages inr eliminating the possibility of vapor locks, it is subject toy a serious cost disadvantage as applied to trucks having a plurality of fuel tanks, in that a separate pump must be provided for each fueltank.

In accordance with this invention,v an electrically` driven, vane-type pump is employed in the fuel system of an internal. combustion engine, and such arrangement finds particular utility in automotive and aircraft;` fuel engine systems. The pump may then be conveniently located adja.- cent the` fuel tank. or at any other convenient point in the fuel line., inasmuch as no mechanical drive connectionsf-rom the engine are required. Such a pumphas dry suction ability and therefore does not need to be submerged within the fuel tank. or mounted gravitatonally below the tank. Such pump will not soak up heat from the engine. Lastly, only one pump is required regardless of the number of tanks on the vehicle, so long as the various tanks are suitably interconnected by a selector cock.

A feature of this invention is the provision of an improved rotary vane pump particularly adaptable for use in a fuel system of an internal combustion engine. The construction of such pump has been unusually simplified and yet such pump includes not only means for pressuring the fuel but also incorporates a pressure limiting device, a fiuid settling chamber, and a filtering screen. Hence ina single pump unit, constructed in accordance with this invention, a multiplicity of necessaryfunctions required for proper operation of an internal combustionengine fuel system are performed.

Furthermore, the electrical control system provided by this invention for control of the energization of the electric motor driving the fuel pump assures the proper operation of the pump during all operating conditions of the internal combustion engine, particularly during the initial starting of the engine, and is so arranged that the fuel pump Will not be actuated when the engine stops for any reason.

Accordingly, it is an object of this invention to provide an improved fuel pump for the fuel system of an internal combustion engine and an improved control system for actuating such pump in accordance with the operating condition of the engine.

Another object of this invention is to provide an improved electrically driven, vane type pump for the fuel system of an internal combustion engine which may be mounted at any convenient point in the fuel system between the fuel tank and the engine.

Still another object of this invention is to provide an improved vane type pump for the fuel system of an internal combustion engine wherein the pump construction is so arranged as to unitarily incorporate a settling chamber and a filtering screen for purifying the fuel in the fuel system and, in addition, a pressure regulating device to limit the maximum fuel pressure produced by the pump.

A further objectV of this invention is to provide a vane type fluid pump characterized by unusual simplicity of construction and ease of manufacture and assemblage, whereby a vane type pump may be produced at a cost permitting price competition with the more commonly used diaphragm type pump.

A particular' object or" this invention is to provide an improved casing for a Vane type pump characterized by the utilization of an end face of the casing, in which both the pump inlet pert and a iiuid supply passage open, to cooperate with a cup-shaped container element to provide a fluid settling chamber. Furthermore, the improved construction permits a filtering screen to be se cured in the path of fluid flow through the settling chamber and such screen requires no separate fastening arrangements, being clamped in position between the cup-shaped container and the casing end face. l

The specific nature of this invention as well as other objects and advantages thereof will become apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings, which, by way of preferred. example only, illustrate one specinc embodiment of the invention.

On the drawings:

Figure 1 is an elevational View of a pump and motor unit embodying this invention;

Figure 2 is an enlarged scale sectional View taken on the plane I-II of Figure l;

Figure 3 is a sectional view taken on the plane III-III of Figure 2;

Figure 4 is a bottom elevational view or" th pump with the settling chamber container removed;

Figure 5 is a top elevational View of the casing member;

Figure 6 is an enlarged scale, sectional view taken on the plane VI-VI of Figure 4;

Figure 7 is a reduced scale, sectional view taken on the plane Vil-VII of Figure 4; and

Figure 8 is a schematic diagram illustrating a fuel system constructed in accordance with this invention and showing the electrical circuit con neotions for energizing the fuel pump motor in accordance with the operating conditions of the internal combustion engine.

As shown on the drawings:

While the pump construction embodying this invention inds particular utility in the fuel system of an automotive or aircraft internal cornbustion engine, those skilled in the art will recognize that such pump is in no manner limited to this specific application but may be employed in any fluid pressuring system.

Referring particularly to Figure l, the pump unit le embodying this invention is preferably1 rigidly secured to a suitable prime mover, such as an electric motor ii. The motor II is or the totally enclosed type, so as to eliminate any possibility of rire hazards when the pump is e ployed in a fuel system. Motor li has an output shaft l la (Figure 2) which is surrounded by an annular extension ange IIc of the motor casing Ilb.

The pump unit le comprises a main casing element i3 which is of generally cup-shaped configuration, having a bottom wall itc of substantial thickness in which a plurality of huid passages are formed in a manner that will be de" scribed. The pump unit le is secured to the flange Hc of the motor casing IIb in any convenient manner, such as by a plurality of bolts i2 which pass through suitable holes Isl? provided in an integral ange I3t formed on the rim of cup-casing I3.

A generally cylindrical liner block Il is snugly inserted within the casing i3 and is supported adjacent the top surface of the easing bottom wall 30, resting upon a washer like thrust plate I5. The liner I4 has a central recess formed therein having an upper concentric portion Iia and a lower portion which is eccentrically located with respect to the axis of the casing I3 and thus provides a pumping chamber I5. Suitable inlet and outlet ports I? and I3 respectively are formed in the bottom wall lc of the casing i3 and have arcuate segmental openings ila and Ita through the top surface of bottom wall 53o and communicate with the pumping chamber I through correspondingly shaped apertures formed in the thrust plate i5.

A rotor I9 is provided having an intermediate cylindrical portion iQa rotatably journaled in the small diameter portion Ilia of the central apertureV in the block ifi. A radially slotted end portion lsb of the rotor projects into the pumping chamber It but, or course, is eccentrically located with respect to the side walls of such chamber. Angularly spaced radial slots Isc are provided in the rotor end ISb and pumping 2O are respectively mounted in such slots and are radially movable therein so as to maintain the radially outer faces or such vanes in engagement with the walls of pumping chamber It as rotor is is rotated.

Rotor IS has a still further reduced diameter shaft portion i3d projecting upwardly out of the liner block; Ill and such portion is internally bored, as indicated at lee to receive the motor shaft i ia therein in co-rotational securement. Preferably, the extreme end of the rotor shaft lia is of noncircular configuration, as indicated at iie and the conforming portion Iif of the rotor recess ie is of similar noncircular configuration so that the rotor iii `will be co-rotatably secured to the motor shaft Ha.

To prevent uid leakage between the periphery of the liner block Il?. and the side walls of pump casing I3, a sealing ring El is provi :.'l which may be conveniently mounted in an lar groove ld provided in the periphery oi the block I4. Likewise, to prevent nui-d leakage tween the rotor IS and the liner a shaft seri-- ing unit 9 is provided in surrounding relations to the rotor extension portion Since t sealing unit may comprise any one of several i known forms, it will not be described in furtherl detail.

While the aforedescribed sealing arrangements are generally adequate to prevent leakage or. fluid, in the event that such leakage does occur, the leakage fluid must be drained away from the motor casing Hb so as to preclude the possibility of such ucl obtaining access to the inte rior of the motor wherein it could possible be ignited by the spark produced at the motor commutator (not shown). Hence, at least a pair oi diametrically opposed drain openings iIf are formed in the bottom edge of the ange Iic of the motor casing I Ib.

As is best shown in Figure 7, the other end I'Eh of the inlet port II opens in the bottom end face i3d of the pump casing i3. The other end 18h of the outlet port I8 communicates with an internally threaded bore of a protuberance I3e by which the outlet of the pump may be connected in conventional manner to the pressure side of the fuel system. Diametrically opposed from protuberance I3@ is a similar internally threaded hollow protuberance I 3f by which the pump may be connected to the low pressure side of the fuel system. The bore of protuberance 53j communicates with a duid supply passage 22 formed in the casing bottom wall I 3c and pasaes-incas sage 22" also opens in the end4 face I'3x/of" casing i532 as indicated at 2 2a;

Acont'ainer 2:3 is provided which is rof generally cupsshaped configuration, having an. outturned rim portion 23a. An annular, depending flange lh is formed on the bottom casing walli i3d and the rim portion 23a. ofA Icontainer 253; -iits snugly within such nange to cooperate with the bottom end wall I'Bd toA denne a fluid settling chamber. Container 23 is conveniently secured tothe casing I3 by a bolt Z4 which passes through a suit able aperture 2312 in the bottom of container 23 and is threaded into the lower portion of a central aperture I3lc formed in the casing I3. The container 23 is maintained in fluid sealed re.- lationship with respect to the casing I3 by an annular seal 25 which is disposed between the container rim 23a and the end wall l3nt of the casing I3, and an O-ring seal 26 which is lcompressed between the head of bolt 24 and the bottom face of container 23.

From the construction thus far described, it is rapparent that the container 23 defines a fluid settling chamber 23o which will permit the gravity separation of extraneous fluids, such las water, from the fuel being supplied to the pump through the supply passage 22, Since the inlet port Il communicates with4 the fluid settling chamber 23e adjacent the top portions thereof, it is apparent that only the lighter weight fuel will be drawn intoV the pumping chamber I5 through the inlet port Il, while heaviery extraneous fluids, such as water, will be collected in the bottom portions of. containerv 23. If desired, container 2 3' may be formedV of. glassy or .other suitable transparent material to facilitate the inspection of itsv fluid contents;

In all internal combustion engine fuel systems, itis desirable, that' the fuel be iiltered' to remove foreign particles therefrom prior to supplying the fuel to the carburetor of the. engine. Such ltering may be conveniently accomplished in a pump embodying this invention by the disposition of a disc-like filtering screen 2'! in a position abuttingk theV bottom face i3d. of the casing I 3. In such position, no special retainingv arrangements need be provided for the. filter 21, inas much as the peripheralv portions ihereof'maybe clamped between the container 23 and the' casing i3, as is clearlyY shown in Figure 2. Since it is generally not desirable to impose a iiltering screen directly across a relatively restricted fuel passage, the screen is apertured as indicated at 21o so as to surround the fluid supply port opening 22a permit unimpededV fluidflow into the settling chamber 23. To provide suiicient support for the central portions of the filter screen 2', an annular sheet metal retainer 2.3 Vis provided which is crimped around the edges lof the screen delining the central opening therein and fits snugly Varound an annular, depending boss ISZ integrally formed on the casing I3. If desired, the retainer 2t may be provided with a flared skirt ,portionA 25a which. functions as a iluid baffle to prevent direct now from fluid mouth 22a ofv iiuid supply passage,- 22. into the mouth I Tb of inlet' port I'I. Instead, such ilaredskirt portion directs the incoming fluidintoy the iiu'id settling chamber 23 and insures thatfgravitational separation of extraneous liquid that mightr be contained in the fuel will be effected.

' It. has already beenmentioned that the. casing bottom I3c is provided with a centralv aperture ISR` which is threaded at its lower end toreceive the bolt 24. The aperture I3k entends;l entirely through the. bottom. wall. I3c and. communicates withthe central. fluid chamber leg formed; at the intersection of the vane slots ISCV in the rotor t3. The thrust plate I5 is of course suitably apertured to. permit such communication. A 'connecting passage 29 is then formed between thev outlet; port I3A andthe top portion of the aperture. |316.' In this manner, a portion ofthe pressured fluid s applied to the inner faces of the varies carried` by the rotor IQ. Hence an outward bias: of such vanes is automatically produced byy such bleed off from the output side of the; pump and the outer ends of the vanes are maintained in snug engagement with the walls ofthe pumping chamber I6.

Lastly, a by-pass'passage 30 is formed in the base portion |30 of the casing I3 providing communication between the outlet port I8 and the fluid settling chamber 23o, as is best shown in Figuresand'?. A relief valve unit 3l is mounted on the bottom face i3d so as to normally maintain the by-pass passage 3e closed. Such relief valve.l may comprise a sheet metal housing Sla of generally cup-shaped configuration but having an integrally formed, projecting mounting ear 3 Ib by which the housing may be secured to the bottom face 13d of the casing I3 by a bolt 33 which passes entirely'through'the base I3c of the casingl I3 and also threadably engages the liner blockV I4 to retain it in its'proper position in the casing1 I3. An additiona1bolt 34 may be provided in diametrically opposed relationship to the bolt 33,' to further secure the liner block Ill in the casing I3.

Within the valve housing 31a an inverted cupshaped valveunit 3io is: mounted for axial move;- ment and is normally biased into sealing relationship-across the by-pass passage 38 by a spring Sid. The maximum. pressure developed in the outlet port I8 will then be limited by the by-pass valve unit 3l andthe value of such maximum depends upon the pressure exerted by the spring 35d- Upon` the attainment of an output pressure of suiicient magnitude to shift the valve 3 Ic from itszseat'againstithe biasing force exerted by spring 31d, the. output port Iii of the pump will then be bled back to. the low pressure or inlet side and hencethe output pressure will decrease until the spring 3 Idcan again close the valve 3 I c. To provideV an unimpeded flow path for iluid bleeding back through. the by-p'ass 33 when the valve 3I'c isv'opened', thevalve housing 3 Ia is provided with alarge aperture 3 I e in its side wall.

From the foregoing description, it is apparent that a pump construction in accordance with this invention. isunusually adaptable to fuel systems for. internal combustion engines for, in addition to accomplishing the pressuring cf the fuel, it alsov accomplishesl the ltering and uid settling functions and limits the output pressure developed by the pump. Furthermore, the entire construction is of such a simplified nature as to permit the pump to beA economically produced by quantity production methods.

The combinedV motor and pump unit may be mounted in any convenient manner upon a vehicle or aircraft. For example, a mounting bracket 35, having apertured mounting flange portions 35d,I may be secured to the combined motor and pump unit by a generally U-shaped ring 3b which engagesin a peripheral groove I Id formed .in the exterior of the motor casing IIb. 'I'he endsof. thering 3% are threadedand project through suitable apertures in mounting bracket v35; andthe ring; isy drawn` into clamping engagement with respect to the motor casing Il by the tightening of nuts 37 upon such threaded end portions.

Since the fuel pump is driven by a prime mover entirely separate from the internal combustion engine to which fuel is to be supplied, the pump may obviously be located at any convenient location on the vehicle or aircraft. Hence, to reduce the possibility of vapor lock, the pump may be conveniently mounted adjacent the fuel tank T of the vehicle, in the manner indicated schematically in Figure 8. In the event that two or more fuel tanks are employed, it will be understood that a suitable selector valve V is provided to selectively connect each of the tanks to la conduit 38 which is in communication with the fluid supply passage 22 of the pump l. In the particular case of an automotive vehicle, the motor and pump unit may be conveniently mounted on either right or left hand longitudinal frame members 35 of the vehicle chassis, as respectively indicated by the dotted and solid lines.

As is clearly shown in Figure 8, this invention provides a novel control circuit for energizing the pump driving motor Ii! in accordance with the operating condition of an internal combustion engine fle. As is customary, the engine 40 embodies a pressured lubricating system and a conventional pressure operated electric switch 4| is provided and mounted on the engine in suchv manner as to eifect the closure of its contacts when a normal range of lubricating pressures is attained in the engine lubricating system. Furthermore, it will be assumed that the engine is provided with an electric starting motor 42 which is energized from the battery B of the Vehicle from a manual or foot controlled switch 43. Also, an ignition switch it is provided which controls the energization of the ignition system of the engine, indicated, schematically at d. With the aforedescribed elements of a conventional internal combustion engine, the driving motor Il of the fuel. pump lll is then connected by a conductor l in series with the contacts of the pressure operated switch and then connected to the cold terminal of the ignition switch ed. Additionally, the motor l l is connected by conductor 50 for energization in parallel with the starter motor 42 whenever the starter motor switch i3 is closed.

With the aforedescribed arrangement, it is apparent that the fuel pump Il) cannot be actuated unless the ignition switch 44 is turned to its on position. .During the starting of the internal combustion engine, the fuel pump is actuated by the energica-tion of its motor l! in parallel with the starting motor ft2. Once the engine has started, the pressure in the lubricating system immediately builds up to a suiiicient value to close the contacts of the pressure operated switch 4l and hence, the fuel pump continues to be actuated so long as a proper range of value of pressure is maintained in the lubricating system.

It is therefore apparent that the described control circuit not onlyT insures that fuel will be supplied to the engine under both starting and running conditions, and the supply of fuel will be interrupted the stopping of the engine, but furthermore, the control circuit functions as a safety system to immediately stop the engine upon a failure of the pressure in the lubricating system, irrespective of the cause f such failure. Such arrangement, of course, is of substantial value inasmuch as it insures that the engine will not be operated without proper lubrication.

It will, of course, be understood that various details of construction may be modified through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

l. A pump comprising a casing having a recess with a multi-ported end face, a pump block in said recess having an end face bottomed on said end face of the casing, said end face of the block having a recess therein overlapping the ports in the end face of the casing, e, vaned rotor in said recess of the block coacting therewith to define a pumping chamber with an inlet portion joined to one port of the casing and an outlet portion joined to another port of the casing through the overlapping portions of the block recess and the ports, said casing having passages extending from said ports, the passage from the port registering with the outlet side of the pump chamber extending through the side of the casing, the passage extending from the port registering with the inlet side of the pump chamber extending to the bottom of the casing, a settling cup on the bottom of the casing communicating with the last-mentioned passage. a filter between said last-menticned passage and the cup, and said casing having an inlet passage communicating with the top of the cup.

2. A fluid pump comprising a casing having an end face, a block disposed on said end face, said block having a recess therein cooperating with said end face to denne a pumping chamber, said end face having an inlet port and an outlet port therein over which said recess in said block extends, a rotor rotatably journalled in said block, a plurality of vanes disposed on said rotor and movable in said chamber for pumping fluid from said inlet port in said end face of said casing to said outlet port in said end face of said casing, a settling cup detachably secured over an end portion of said casing, said casing having an inlet and an outlet in side portions thereof, said end portion of said casing having a plurality of openings therein, said casing having a supply passage therein extending from said inlet in a side portion thereof to one of said plurality of openings in said end portion thereof, said casing having a second passage therein extending from another of said plurality of openings in the end portion thereof to said inlet port in said end face thereof, and said casing having a third passage therein extending from said outlet port in the end face thereof to said outlet in the side portion thereof.

3 A :duid pump comprising a casing having an end facey a block disposed on said end face, said block having a recess therein cooperating with said end face to denne a pumping chamber, said end face having an inlet port and an outlet port therein over which said recess in said block extends, a rotor rotatably journalled in said block, a plurality of vanes disposed on said rotor and movable in said chamber for pumping fluid from said inlet port in said end face of said casing to said outlet port in said end face of said casing, a settling cup detachably secured over an end portion of said casing, said casing having an inlet and an outlet in side portions thereof, said end portion of said casing having a plurality of openings therein, said casing having a supply passage therein extending from said inlet in a side portion thereof to one of said plurality of openings in said end portion thereof, said casing having a second passage therein extending from another of said plurality of openings in said end portion thereof to said inlet port in said end face thereof, a filter screen between said last mentioned opening and said cup, and said casing having a third passage therein extending from said outlet port in the end face thereof to said outlet in the side portion thereof.

4. A fluid pump comprising a casing having an end face, a block disposed on said end face, said block having a recess therein cooperating with said end face to dene a pumping chamber, said end face having an inlet port and an outlet port therein over which said recess in said block extends, a rotor rotatably journalled in said block, a plurality of vanes disposed on said rotor and movable in said chamber for pumping fluid from said inlet port in said end face of said casing to said outlet port in said end face of said casing, a settling cup detachably secured over an end portion of said casing, said casing having an inlet and an outlet in side portions thereof, said end portion of said casing having a plurality of openings therein, said casing having a supply passage therein extending from said inlet in a side portion thereof to one of said plurality of openings in said end portion thereof, said casing having a second passage therein extending from another of said plurality of openings in the end portion thereof to said inlet port in said end face thereof, said casing having a third passage therein extending from said inlet port in the end face thereof to said outlet in the side portion thereof, and said casing having a fourth passage extending from another of said plurality of openings in the end portion thereof and communicating with said third passage therein, and a relief valve disposed in said fourth passage in said casing.

5. A fluid pump comprising a casing having an end face, a block disposed on said end face, said block having a recess therein cooperating with said end face to define a pumping chamber, said end face having an inlet port and an outlet port therein over which said recess in said block extends, a rotor rotatably journalled in said block, a plurality of vanes disposed on said rotor and movable in said chamber for pumping fluid from said inlet port in said end face of said casing to said outlet port in said end face of said casing, a

10 settling cup detachably secured over an end portion of said casing, said casing having an inlet and an outlet in side portions thereof, said end portion of said casing having a plurality of openings therein, said casing having a supply passage therein extending from said inlet in a side portion thereof to one of said plurality of openings in said end portion thereof, said casing having a second passage therein extending from another of said plurality of openings in the end portion thereof to said inlet port in said end face thereof, said casing having a third passage therein extending from said outlet port in the end face thereof to said outlet in the side portion thereof, and said casing having a fourth passage extending from another of said plurality of openings in the end portion thereof and communicating with said third passage therein, a relief valve disposed in said fourth passage, and a threaded fastener securing said relief valve to said casing and projecting into said block to secure said block to said end face.

6. A pump comprising a casing having a recess with a multi-ported end face, a pump block journaled in said recess and having an end face bottomed on said end face of the casing, said end face of the block having a recess therein overlapping the ports in the end face of the casing, and a vaned rotor in said recess of the block and coacting therewith to define a pumping chamber, said casing having inlet and outlet passages communicating with said ports.

THEODORE R. THOREN.

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